aboutsummaryrefslogtreecommitdiff
path: root/loginutils/adduser.c
blob: cfaf860e06bd7086b6f2bd3a8c6ead35a0a6246e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
/* vi: set sw=4 ts=4: */
/*
 * adduser - add users to /etc/passwd and /etc/shadow
 *
 * Copyright (C) 1999 by Lineo, inc. and John Beppu
 * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "busybox.h"



/* structs __________________________ */

typedef struct {
	uid_t u;
	gid_t g;
} Id;

/* data _____________________________ */

/* defaults : should this be in an external file? */
static const char default_passwd[] = "x";
static const char default_gecos[] = "Linux User,,,";
static const char default_home_prefix[] = "/home";
static const char default_shell[] = "/bin/sh";

#ifdef CONFIG_FEATURE_SHADOWPASSWDS
/* shadow in use? */
static int shadow_enabled = 0;
#endif

/* remix */
/* EDR recoded such that the uid may be passed in *p */
static int passwd_study(const char *filename, struct passwd *p)
{
	struct passwd *pw;
	FILE *passwd;

	const int min = 500;
	const int max = 65000;

	passwd = bb_wfopen(filename, "r");
	if (!passwd)
		return 4;

	/* EDR if uid is out of bounds, set to min */
	if ((p->pw_uid > max) || (p->pw_uid < min))
		p->pw_uid = min;

	/* stuff to do:  
	 * make sure login isn't taken;
	 * find free uid and gid;
	 */
	while ((pw = fgetpwent(passwd))) {
		if (strcmp(pw->pw_name, p->pw_name) == 0) {
			/* return 0; */
			return 1;
		}
		if ((pw->pw_uid >= p->pw_uid) && (pw->pw_uid < max)
			&& (pw->pw_uid >= min)) {
			p->pw_uid = pw->pw_uid + 1;
		}
	}

	/* EDR check for an already existing gid */
	while (getgrgid(p->pw_uid) != NULL)
		p->pw_uid++;

	/* EDR also check for an existing group definition */
	if (getgrnam(p->pw_name) != NULL)
		return 3;

	/* EDR bounds check */
	if ((p->pw_uid > max) || (p->pw_uid < min))
		return 2;

	/* EDR create new gid always = uid */
	p->pw_gid = p->pw_uid;

	/* return 1; */
	return 0;
}

static void addgroup_wrapper(const char *login, gid_t gid)
{
	char *cmd;

	bb_xasprintf(&cmd, "addgroup -g %d %s", gid, login);
	system(cmd);
	free(cmd);
}

static void passwd_wrapper(const char *login) __attribute__ ((noreturn));

static void passwd_wrapper(const char *login)
{
	static const char prog[] = "passwd";
	execlp(prog, prog, login, NULL);
	bb_error_msg_and_die("Failed to execute '%s', you must set the password for '%s' manually", prog, login);
}

/* putpwent(3) remix */
static int adduser(const char *filename, struct passwd *p)
{
	FILE *passwd;
	int r;
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
	FILE *shadow;
	struct spwd *sp;
#endif

	/* make sure everything is kosher and setup uid && gid */
	passwd = bb_wfopen(filename, "a");
	if (passwd == NULL) {
		return 1;
	}
	fseek(passwd, 0, SEEK_END);

	/* if (passwd_study(filename, p) == 0) { */
	r = passwd_study(filename, p);
	if (r) {
		if (r == 1)
			bb_error_msg("%s: login already in use", p->pw_name);
		else if (r == 2)
			bb_error_msg("illegal uid or no uids left");
		else if (r == 3)
			bb_error_msg("group name %s already in use", p->pw_name);
		else
			bb_error_msg("generic error.");
		return 1;
	}

	/* add to passwd */
	if (putpwent(p, passwd) == -1) {
		return 1;
	}
	fclose(passwd);

#ifdef CONFIG_FEATURE_SHADOWPASSWDS
	/* add to shadow if necessary */
	if (shadow_enabled) {
		shadow = bb_wfopen(bb_path_shadow_file, "a");
		if (shadow == NULL) {
			return 1;
		}
		fseek(shadow, 0, SEEK_END);
		sp = pwd_to_spwd(p);
		sp->sp_max = 99999;		/* debianish */
		sp->sp_warn = 7;
		fprintf(shadow, "%s:!:%ld:%ld:%ld:%ld:::\n",
				sp->sp_namp, sp->sp_lstchg, sp->sp_min, sp->sp_max,
				sp->sp_warn);
		fclose(shadow);
	}
#endif

	/* add to group */
	/* addgroup should be responsible for dealing w/ gshadow */
	addgroup_wrapper(p->pw_name, p->pw_gid);

	/* Clear the umask for this process so it doesn't
	 * * screw up the permissions on the mkdir and chown. */
	umask(0);

	/* mkdir */
	if (mkdir(p->pw_dir, 0755)) {
		bb_perror_msg("%s", p->pw_dir);
	}
	/* Set the owner and group so it is owned by the new user. */
	if (chown(p->pw_dir, p->pw_uid, p->pw_gid)) {
		bb_perror_msg("%s", p->pw_dir);
	}
	/* Now fix up the permissions to 2755. Can't do it before now
	 * since chown will clear the setgid bit */
	if (chmod(p->pw_dir, 02755)) {
		bb_perror_msg("%s", p->pw_dir);
	}
	/* interactively set passwd */
	passwd_wrapper(p->pw_name);
}


/* return current uid (root is always uid == 0, right?) */
static inline uid_t i_am_not_root(void)
{
	return geteuid();
}

/*
 * adduser will take a login_name as its first parameter.
 *
 * home
 * shell
 * gecos 
 *
 * can be customized via command-line parameters.
 * ________________________________________________________________________ */
int adduser_main(int argc, char **argv)
{
	int opt;
	const char *login;
	const char *gecos;
	const char *home = NULL;
	const char *shell;

	struct passwd pw;

	/* init */
	if (argc < 2) {
		bb_show_usage();
	}
	gecos = default_gecos;
	shell = default_shell;

	/* get args */
	while ((opt = getopt (argc, argv, "h:g:s:")) != -1)
		switch (opt) {
			case 'h':
				home = optarg;
				break;
			case 'g':
				gecos = optarg;
				break;
			case 's':
				shell = optarg;
				break;
			default:
				bb_show_usage();
				break;
		}

	/* got root? */
	if (i_am_not_root()) {
		bb_error_msg_and_die( "Only root may add a user or group to the system.");
	}

	/* get login */
	if (optind >= argc) {
		bb_error_msg_and_die( "no user specified");
	}
	login = argv[optind];

	/* create string for $HOME if not specified already */
	if (!home) {
		home = concat_path_file(default_home_prefix, login);
	}
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
	/* is /etc/shadow in use? */
	shadow_enabled = (0 == access(bb_path_shadow_file, F_OK));
#endif

	/* create a passwd struct */
	pw.pw_name = (char *)login;
	pw.pw_passwd = (char *)default_passwd;
	pw.pw_uid = 0;
	pw.pw_gid = 0;
	pw.pw_gecos = (char *)gecos;
	pw.pw_dir = (char *)home;
	pw.pw_shell = (char *)shell;

	/* grand finale */
	return adduser(bb_path_passwd_file, &pw);
}

/* $Id: adduser.c,v 1.5 2003/03/19 09:12:20 mjn3 Exp $ */